Ultra-thin silver films obtained by sequential quench-anneal processing

We have used the “two-step” growth technique, quench condensing followed by an anneal, to grow ultra-thin films of silver on glass substrates. As has been seen with semiconductor substrates this process produces a metastable homogeneous covering of silver. By measuring the in situ resistance of the film during growth we are able to see that the low temperature growth onto substrates held at 100 K produces a precursor phase that is insulating until the film has been annealed. The transformation of the precursor phase into the final, metallic silver film occurs at a characteristic temperature near 150 K where the sample reconstructs. This reconstruction is accompanied by a decrease in resistance of up to 10 orders of magnitude.